The invention refers to a method of fractionation of hydrocarbon material (oil) and may be applied in installations with an atmospheric column, and those equipped with both an atmospheric and a vacuum column, intended for fractional distillation of oil.
Practical field of industrial application of the invention covers oil-processing, chemical and other industries related to processing of liquids containing bound hydrogen, primarily—hydrocarbon liquids, such as gas distillate, crude oil, intermediate and finished products of oil processing, etc.
Methods of acoustic excitation of liquids are well-known from state of the art. These methods comprise transfer of vibrational energy to a liquid by means of a source of mechanical vibrations interacting with the liquid, where the source in question may be presented by mechanical, electromechanical, magnetostrictive, piezoelectric, hydrodynamic and other types of acoustic radiators. In particular, patent RU 2149886 describes a method of resonant excitation of oil and other liquids containing bound hydrogen, by means of vibrating effect on a fluid aimed at destructive transformation of its chemical bonds on the molecular level.
All of these well-known methods of acoustic excitation of liquids for destructive transformation of their chemical bonds are characterized by a shortcoming, lying in the lack of definite criteria for selection of particular resonance frequencies, which may substantially reduce efficiency of acoustic pretreatment of liquids.
International publication WO 94/10261 also describes a method and a device for pretreatment and fractionation of hydrocarbon liquids by means of a hydrodynamic acoustic radiator of the rotor type. The method of pretreatment of liquids comprises consecutive supply of fluid into cavities of a number of impellers, release of liquid from the cavity of each of these impellers into the stator cavity through the impeller outlets and the stator bypass ports, the peripheral face of the impellers being separated from the stator by the smallest possible gap. The streams of liquid flowing out of the impeller outlets undergo periodic interruptions, which excite sound frequency mechanical vibrations in the liquid. The device for pretreatment of liquids comprises a rotor including a shaft supported by bearings and a number of impellers mounted on the shaft. Each of the impellers is made in the form of a disc with a peripheral circular wall, where a series of outlets for liquid are uniformly distributed along the circle. The device contains a is stator having an inlet and an outlet for liquid, as well as coaxial walls adjacent to the circular peripheral wall of each of the impellers with the smallest technologically feasible gap, a number of bypass holes for liquid made in each of the coaxial walls. A device for fractionation of hydrocarbon liquids is coupled with a device for their pretreatment and contains a chamber for separation of pretreated liquid into liquid and vapor phases (conjugated with the last impeller) and a communicating chamber for condensation of the vapor phase.
However, the above-described method and device for pretreatment of hydrocarbon liquids do not allow for such pretreatment potentiality to be realized to its full extent, which would make fractionation of the pretreated liquid more efficient.
International publication WO 96/33011 also describes a method and a device for conditioning of hydrocarbon liquids by means of a hydrodynamic source of mechanical vibrations. The method comprises supply of liquid into the cavity of an impeller rotating inside a stator, release of liquid from the cavity of the impeller through a series of outlets distributed uniformly along its peripheral face into a circular chamber confined with the peripheral face of the impeller and the internal coaxial surface of the stator, and liquid extraction from the circular chamber. Liquid is preferably extracted from the circular chamber into the stator collection chamber through a series of bypass holes distributed uniformly along the stator internal coaxial surface, which are located, one after another, against the outlets of the impeller, while the latter is rotating. Here the nominal value of radius R of the impeller peripheral face and its nominal rotation speed n are set depending on selected number K of its outlets, according to the following empirical relations:R=1.1614 K mm,n=3.8396 K−3/2·106 rpm.
The device contains a rotor, which comprises a shaft supported by bearings and at least one impeller mounted on the shaft. This impeller is made as a disc with a peripheral circular wall, where outlets are holes distributed uniformly along the circle. The stator has a wall coaxial to the impeller, an inlet for supply of liquid communicating to the impeller cavity and an outlet for liquid extraction. There is a circular chamber formed by the stator coaxial wall and the impeller peripheral circular wall, which communicates with the stator outlet. The stator preferably has a collection chamber communicating, on the one side, with its outlet, and on the other side, with the circular chamber, through a series of bypass holes made in the stator coaxial wall and distributed uniformly along the circle. Means for driving the rotor with a predetermined speed are provided.
The above-described method and device of conditioning hydrocarbon liquids have made an efficient effort to find the optimum relation between the determinative operating parameters such as the radius of the impeller peripheral face and the impeller rotation speed. However potentiality of such pretreatment of hydrocarbon liquids to optimize their fractionation efficiency is not exhausted yet.
A method of fractionation of hydrocarbon liquids by means of distillation is also known from state of the art, which implies pretreatment of a liquid to be fractionated according to the method described, e.g. in the above-mentioned international publication WO 96/33011, through supply of pretreated liquid into the rectifying column and extraction of the distillated and residual fractions.
Installations for fractionation of hydrocarbon liquids through distillation are also known from the state of the art, these installations comprising a feed pump connected by pipelines to at least one rectifying column. For instance, application of a primary rotor hydrodynamic device in such installations for pretreatment of the liquid to be fractionated is known from the above-mentioned international publication WO 96/33011.
Similar methods and installations for fractionation of hydrocarbon liquids through using a primary rotor hydrodynamic device for their pretreatment make it possible to increase output of the most valuable light ends. However, in practice, potentiality of such technology remains unrealized to its full extent. Among the reasons are both insufficient efficiency of the rotor hydrodynamic device for pretreatment of liquid, and not quite rational way of integrating this device into conventional schemes of installations for fractionation of hydrocarbon liquids.
A method of processing of oil-containing tailings according to RF patent No. 2215775 of Nov. 10, 2003 is also known from state of the art. This method implies supply of raw material into the processing zone, processing of the raw material by wave action produced through formation of a wide range of frequencies (from the acoustic to the light ones) in the medium to be processed with subsequent thermal cracking of the action products implemented in the mode of oil primary distillation and obtaining finished products from the vapor phase, and an installation for fractionation of hydrocarbon material, which comprises the following communicating units: a device for processing feed stock implemented as an operating container, a generator and radiator of acoustic vibrations, which comprise a generator and a radiator of acoustic vibrations and an additional generator of electromagnetic vibrations electrically connected to a radiating aerial located inside the operating container and made in the form of two radiating circuits arranged inside a cylinder housing, each of these circuits comprising a series of transversal parallel perforated metal plates fixed rigidly on the wall of the housing, where the circuits are made of metal with different electronegativity, and the plates of one of the circuits are located between the plates of the other circuit, and where the housing of the above-mentioned radiator is made of a dielectric material possessing a piezoelectric property, the device for extraction of finished products contains a cracking tank for processed products, which is connected to a refluxer-distiller, and accumulating containers for the finished product and residual products of cracking. The generator of electromagnetic vibrations may be realized as an electric spark arrester. The generator of acoustic vibrations is an electric centrifugal pump mounted on a pipeline at the inlet of the container, while the radiator of acoustic vibrations is represented by the pipeline supplying the material into the container and the walls of this container.
This solution has a shortcoming: the design of the generator of electromagnetic vibrations in the installation of hydrocarbon material fractionation is complicated, its parameters are to be selected depending on the quality of the material, selectivity of the effect produced by the device on the material to be processed is obtained by selection of materials the to aerial plates and the dielectric housing are made of. Therefore the design in question cannot be efficiently applied for processing materials of different quality, without undergoing reconstruction (which is laborious in itself) accomplished by experimental matching of separate units of processing equipment. Moreover, obligatory involvement of an electric pump in processing as a source of acoustic vibrations of the pipeline walls significantly reduces the effect produced upon the medium being processed.